1 /* can_quekern.c - CAN message queues functions for the Linux kernel
2 * Linux CAN-bus device driver.
3 * New CAN queues by Pavel Pisa - OCERA team member
4 * email:pisa@cmp.felk.cvut.cz
5 * This software is released under the GPL-License.
6 * Version lincan-0.2 9 Jul 2003
9 #include "../include/can.h"
10 #include "../include/can_sysdep.h"
11 #include "../include/can_queue.h"
15 extern atomic_t edge_num_cnt;
18 #define DEBUGQUE(fmt,args...) printk(KERN_ERR "can_queue (debug): " fmt,\
22 #define DEBUGQUE(fmt,args...)
25 #define ERRMSGQUE(fmt,args...) printk(KERN_ERR "can_queue: " fmt,\
30 * Modifies Tx message processing
31 * 0 .. local message processing disabled
32 * 1 .. local messages disabled by default but can be enabled by canque_set_filt
33 * 2 .. local messages enabled by default, can be disabled by canque_set_filt
35 extern int processlocal;
37 void canque_dead_func(unsigned long data);
39 /* Support for dead ends structures left after client close */
40 can_spinlock_t canque_dead_func_lock;
41 LIST_HEAD(canque_dead_ends);
42 /* retrieved by list_entry(canque_dead_ends.next,struct canque_ends_t,dead_peers) */
43 LIST_HEAD(canque_dead_edges);
44 /* retrieved by list_entry(canque_dead_edges.next,struct canque_edge_t,inpeers) */
45 DECLARE_TASKLET(canque_dead_tl, canque_dead_func, 0);
46 /* activated by tasklet_schedule(&canque_dead_tl) */
50 struct canque_edge_t *canque_dead_edges_cut_first(void)
52 can_spin_irqflags_t flags;
53 struct canque_edge_t *edge;
54 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
55 if(list_empty(&canque_dead_edges))
58 edge=list_entry(canque_dead_edges.next,struct canque_edge_t,inpeers);
59 list_del(&edge->inpeers);
61 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
65 void canque_dead_func(unsigned long data)
67 can_spin_irqflags_t flags;
68 struct canque_edge_t *qedge;
69 struct canque_ends_t *qends;
70 struct list_head *entry;
72 while((qedge=canque_dead_edges_cut_first())){
73 DEBUGQUE("edge %d disposed\n",qedge->edge_num);
77 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
78 entry=canque_dead_ends.next;
79 can_spin_unlock_irqrestore(&canque_dead_func_lock,flags);
80 while(entry!=&canque_dead_ends){
81 qends=list_entry(canque_dead_ends.next,struct canque_ends_t,dead_peers);
83 if(!list_empty(&qends->inlist))
85 if(!list_empty(&qends->outlist))
87 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
88 list_del(&qends->dead_peers);
89 can_spin_unlock_irqrestore(&canque_dead_func_lock,flags);
90 DEBUGQUE("ends structure disposed\n");
97 void canque_edge_do_dead(struct canque_edge_t *edge, int dead_fl)
99 can_spin_irqflags_t flags;
103 if(canqueue_disconnect_edge(edge)<0){
104 ERRMSGQUE("canque_edge_do_dead: canqueue_disconnect_edge failed !!!\n");
108 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
109 list_add(&edge->inpeers,&canque_dead_edges);
110 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
111 tasklet_schedule(&canque_dead_tl);
116 /*if(qends->ends_flags & CAN_ENDSF_DEAD){
117 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
118 list_del(&qends->dead_peers);
119 list_add(&qends->dead_peers,&canque_dead_ends);
120 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
121 tasklet_schedule(&canque_dead_tl);
126 * canqueue_notify_kern - notification callback handler for Linux userspace clients
127 * @qends: pointer to the callback side ends structure
128 * @qedge: edge which invoked notification
129 * @what: notification type
131 void canqueue_notify_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge, int what)
133 DEBUGQUE("canqueue_notify_kern for edge %d, use %d and event %d\n",
134 qedge->edge_num,(int)atomic_read(&qedge->edge_used),what);
136 case CANQUEUE_NOTIFY_EMPTY:
137 wake_up(&qends->endinfo.fileinfo.emptyq);
138 if(canque_fifo_test_and_clear_fl(&qedge->fifo, FREEONEMPTY))
139 canque_edge_decref(qedge);
141 case CANQUEUE_NOTIFY_SPACE:
142 wake_up(&qends->endinfo.fileinfo.writeq);
143 #ifdef CAN_ENABLE_KERN_FASYNC
144 /* Asynchronous I/O processing */
145 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_OUT);
146 #endif /*CAN_ENABLE_KERN_FASYNC*/
148 case CANQUEUE_NOTIFY_PROC:
149 wake_up(&qends->endinfo.fileinfo.readq);
150 #ifdef CAN_ENABLE_KERN_FASYNC
151 /* Asynchronous I/O processing */
152 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_IN);
153 #endif /*CAN_ENABLE_KERN_FASYNC*/
155 case CANQUEUE_NOTIFY_NOUSR:
156 wake_up(&qends->endinfo.fileinfo.readq);
157 wake_up(&qends->endinfo.fileinfo.writeq);
158 wake_up(&qends->endinfo.fileinfo.emptyq);
160 case CANQUEUE_NOTIFY_DEAD_WANTED:
161 case CANQUEUE_NOTIFY_DEAD:
162 if(canque_fifo_test_and_clear_fl(&qedge->fifo, READY))
163 canque_edge_decref(qedge);
165 case CANQUEUE_NOTIFY_ATTACH:
171 * canqueue_ends_init_kern - Linux userspace clients specific ends initialization
172 * @qends: pointer to the callback side ends structure
174 int canqueue_ends_init_kern(struct canque_ends_t *qends)
176 canqueue_ends_init_gen(qends);
178 init_waitqueue_head(&qends->endinfo.fileinfo.readq);
179 init_waitqueue_head(&qends->endinfo.fileinfo.writeq);
180 init_waitqueue_head(&qends->endinfo.fileinfo.emptyq);
181 #ifdef CAN_ENABLE_KERN_FASYNC
182 qends->endinfo.fileinfo.fasync=NULL;
183 #endif /*CAN_ENABLE_KERN_FASYNC*/
185 qends->notify=canqueue_notify_kern;
186 DEBUGQUE("canqueue_ends_init_kern\n");
192 * canque_get_inslot4id_wait_kern - find or wait for best outgoing edge and slot for given ID
193 * @qends: ends structure belonging to calling communication object
194 * @qedgep: place to store pointer to found edge
195 * @slotp: place to store pointer to allocated slot
196 * @cmd: command type for slot
197 * @id: communication ID of message to send into edge
198 * @prio: optional priority of message
200 * Same as canque_get_inslot4id(), except, that it waits for free slot
201 * in case, that queue is full. Function is specific for Linux userspace clients.
202 * Return Value: If there is no usable edge negative value is returned.
204 int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,
205 struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
206 int cmd, unsigned long id, int prio)
209 DEBUGQUE("canque_get_inslot4id_wait_kern for cmd %d, id %ld, prio %d\n",cmd,id,prio);
210 wait_event_interruptible((qends->endinfo.fileinfo.writeq),
211 (ret=canque_get_inslot4id(qends,qedgep,slotp,cmd,id,prio))!=-1);
216 * canque_get_outslot_wait_kern - receive or wait for ready slot for given ends
217 * @qends: ends structure belonging to calling communication object
218 * @qedgep: place to store pointer to found edge
219 * @slotp: place to store pointer to received slot
221 * The same as canque_test_outslot(), except it waits in the case, that there is
222 * no ready slot for given ends. Function is specific for Linux userspace clients.
223 * Return Value: Negative value informs, that there is no ready output
224 * slot for given ends. Positive value is equal to the command
225 * slot has been allocated by the input side.
227 int canque_get_outslot_wait_kern(struct canque_ends_t *qends,
228 struct canque_edge_t **qedgep, struct canque_slot_t **slotp)
231 DEBUGQUE("canque_get_outslot_wait_kern\n");
232 wait_event_interruptible((qends->endinfo.fileinfo.readq),
233 (ret=canque_test_outslot(qends,qedgep,slotp))!=-1);
238 * canque_sync_wait_kern - wait for all slots processing
239 * @qends: ends structure belonging to calling communication object
240 * @qedge: pointer to edge
242 * Functions waits for ends transition into empty state.
243 * Return Value: Positive value indicates, that edge empty state has been reached.
244 * Negative or zero value informs about interrupted wait or other problem.
246 int canque_sync_wait_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
249 DEBUGQUE("canque_sync_wait_kern\n");
250 wait_event_interruptible((qends->endinfo.fileinfo.emptyq),
251 (ret=canque_fifo_test_fl(&qedge->fifo,EMPTY)?1:0));
257 * canque_new_edge_kern - allocate new edge structure in the Linux kernel context
258 * @slotsnr: required number of slots in the newly allocated edge structure
260 * Return Value: Returns pointer to allocated slot structure or %NULL if
261 * there is not enough memory to process operation.
263 struct canque_edge_t *canque_new_edge_kern(int slotsnr)
265 struct canque_edge_t *qedge;
266 qedge = (struct canque_edge_t *)kmalloc(sizeof(struct canque_edge_t), GFP_KERNEL);
267 if(qedge == NULL) return NULL;
269 memset(qedge,0,sizeof(struct canque_edge_t));
270 can_spin_lock_init(&qedge->fifo.fifo_lock);
271 if(canque_fifo_init_slots(&qedge->fifo, slotsnr)<0){
273 DEBUGQUE("canque_new_edge_kern failed\n");
276 atomic_set(&qedge->edge_used,1);
278 qedge->filtmask = canque_filtid2internal(0l, (processlocal<2)? MSG_LOCAL:0);
279 qedge->edge_prio = 0;
281 /* not exactly clean, but enough for debugging */
282 atomic_inc(&edge_num_cnt);
283 qedge->edge_num=atomic_read(&edge_num_cnt);
284 #endif /* CAN_DEBUG */
285 DEBUGQUE("canque_new_edge_kern %d\n",qedge->edge_num);
289 #ifdef USE_SYNC_DISCONNECT_EDGE_KERN
292 * canqueue_disconnect_edge_kern - disconnect edge from communicating entities with wait
293 * @qends: ends structure belonging to calling communication object
294 * @qedge: pointer to edge
296 * Same as canqueue_disconnect_edge(), but tries to wait for state with zero
298 * Return Value: Negative value means, that edge is used and cannot
299 * be disconnected yet. Operation has to be delayed.
301 int canqueue_disconnect_edge_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
303 canque_fifo_set_fl(&qedge->fifo,BLOCK);
304 DEBUGQUE("canqueue_disconnect_edge_kern %d called\n",qedge->edge_num);
305 if(!canque_fifo_test_and_set_fl(&qedge->fifo,DEAD)){
306 canque_notify_bothends(qedge, CANQUEUE_NOTIFY_DEAD);
308 if(atomic_read(&qedge->edge_used)>0)
309 atomic_dec(&qedge->edge_used);
311 DEBUGQUE("canqueue_disconnect_edge_kern %d waiting\n",qedge->edge_num);
312 wait_event((qends->endinfo.fileinfo.emptyq),
313 (canqueue_disconnect_edge(qedge)>=0));
315 /*set_current_state(TASK_UNINTERRUPTIBLE);*/
316 /*schedule_timeout(HZ);*/
319 DEBUGQUE("canqueue_disconnect_edge_kern cannot set DEAD\n");
325 int canqueue_disconnect_list_kern(struct canque_ends_t *qends, struct list_head *list)
327 struct canque_edge_t *edge;
328 can_spin_irqflags_t flags;
330 can_spin_lock_irqsave(&qends->ends_lock,flags);
331 if(list_empty(list)){
332 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
335 if(list == &qends->inlist)
336 edge=list_entry(list->next,struct canque_edge_t,inpeers);
338 edge=list_entry(list->next,struct canque_edge_t,outpeers);
339 atomic_inc(&edge->edge_used);
340 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
341 if(canqueue_disconnect_edge_kern(qends, edge)>=0) {
342 /* Free edge memory */
343 canque_fifo_done(&edge->fifo);
346 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
347 canque_edge_decref(edge);
348 DEBUGQUE("canqueue_disconnect_list_kern in troubles\n");
349 DEBUGQUE("the edge %d has usage count %d and flags %ld\n",edge->edge_num,atomic_read(&edge->edge_used),edge->fifo.fifo_flags);
355 #endif /*USE_SYNC_DISCONNECT_EDGE_KERN*/
358 int canqueue_ends_sync_all_kern(struct canque_ends_t *qends)
360 struct canque_edge_t *qedge;
362 canque_for_each_inedge(qends, qedge){
363 DEBUGQUE("canque_sync_wait_kern called for edge %d\n",qedge->edge_num);
364 canque_sync_wait_kern(qends, qedge);
370 * canqueue_ends_dispose_kern - finalizing of the ends structure for Linux kernel clients
371 * @qends: pointer to ends structure
372 * @sync: flag indicating, that user wants to wait for processing of all remaining
375 * Return Value: Function should be designed such way to not fail.
377 int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync)
379 can_spin_irqflags_t flags;
382 DEBUGQUE("canqueue_ends_dispose_kern\n");
383 canqueue_block_inlist(qends);
384 canqueue_block_outlist(qends);
386 /*Wait for sending of all pending messages in the output FIFOs*/
388 canqueue_ends_sync_all_kern(qends);
390 /* Finish or kill all outgoing edges listed in inends */
391 delayed=canqueue_ends_kill_inlist(qends, 1);
392 /* Kill all incoming edges listed in outends */
393 delayed|=canqueue_ends_kill_outlist(qends);
395 wake_up(&qends->endinfo.fileinfo.readq);
396 wake_up(&qends->endinfo.fileinfo.writeq);
397 wake_up(&qends->endinfo.fileinfo.emptyq);
400 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
401 qends->ends_flags |= CAN_ENDSF_DEAD;
402 list_add(&qends->dead_peers,&canque_dead_ends);
403 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
404 tasklet_schedule(&canque_dead_tl);
406 DEBUGQUE("canqueue_ends_dispose_kern delayed\n");
411 DEBUGQUE("canqueue_ends_dispose_kern finished\n");
415 void canqueue_kern_initialize()